Drum type washing machine

ABSTRACT

In a drum type washing machine according to the present invention, an electrolytic device  60  for electrolyzing water stored in an outer tub  2  is attached to an outer peripheral surface wall  21  of the outer tub  2 . The water stored in the outer tub  2  flows into an electrolytic tub  62  through an inlet tube  64 A and a connection tube  63 A, and is electrolyzed by a plurality of electrode plates  61 , after which it is returned to the outer tub  2  through a connection tube  63 B and an outlet tube  64 B. The electrolyzed water contains active oxygen (O 2   − ), hypochlorous acid (HClO), etc. having a sterilizing effect. Accordingly, the detergency is improved.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a drum type washing machine.

[0003] 2. Description of Prior Art

[0004] Conventionally, a drum type washing machine for doing washing with laundry put in a cylindrical drum. This type of washing machine has an outer tub surrounding the outside of the drum, and does washing by repeating operations of rotating the drum with a predetermined amount of water stored in the outer tub, to lift the laundry in the drum using a baffle provided in a protruding state on an inner surface of the drum and naturally drop the laundry toward the surface of the water from a certain degree of height. In the drum type washing machine, it is desired that the detergency thereof is improved.

SUMMARY OF THE INVENTION

[0005] An object of the present invention is to provide a drum type washing machine whose detergency is improved.

[0006] The present invention is directed to a drum type washing machine comprising an electrolytic device having an electrode plate provided, when water is stored in an outer tub, at a position where it is immersed in the stored water such that the stored water can be electrolyzed.

[0007] According to the present invention, the water is electrolyzed by the electrolytic device, thereby producing active oxygen (O₂ ⁻), hypochlorous acid (HClO), etc. The functions of the products can prevent dirt removed from laundry from adhering to the laundry again at the time of washing and can sterilize the laundry by a sterilizing effect at the time of rinsing. Consequently, the detergency can be improved.

[0008] When an electrolytic tub is provided opposite to a peripheral surface wall of a drum, the water stored in the outer tub which flows as the drum is rotated smoothly enters the electrolytic tub. Consequently, the electrolysis of the water is speeded up.

[0009] Furthermore, the electrolytic tub may be attached such that an inlet thereto faces the tangent of the peripheral surface wall. In this case, the water stored in the outer tub which flows as the drum is rotated smoothly enters the electrolytic device. Consequently, the electrolysis of the water can be speeded up.

[0010] Furthermore, it is preferable that the electrolytic tub is attached obliquely so as to be parallel to a surface of the outer tub at a lower corner of a cylindrical portion of the outer tub. In this case, the electrolytic device can be arranged in a narrow mounting space.

[0011] Furthermore, the electrolytic tub may be provided opposite to an end surface of the drum. In this case, waste thread or the like contained in the water stored in the outer tub can be prevented from entering the electrolytic device, thereby making it possible to prevent breakdown of the electrolytic device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a perspective view showing a drum type washing machine according to an embodiment of the present invention as viewed obliquely from above;

[0013]FIG. 2 is a longitudinal sectional view showing the overall configuration of a drum type washing machine, where a cross section through the washing machine cut along a vertical surface in a right-and-left direction is viewed from the front;

[0014]FIG. 3 is a longitudinal sectional view of a drum type washing machine, where a cross section through the washing machine cut along a vertical surface in a front-and-rear direction is viewed from the left;

[0015]FIG. 4 is a longitudinal sectional view of a drum type washing machine, where a cross section through the washing machine cut along a vertical surface in a front-and-rear direction is viewed from the right;

[0016]FIG. 5 is a right side view showing an outer tub viewed in a case where it is taken out;

[0017]FIG. 6 is a front view showing an outer tub viewed in a case where it is taken out; and

[0018]FIG. 7 is a longitudinal sectional view showing the overall configuration of a drum type washing machine according to another embodiment of the present invention, where a cross section through the washing machine cut along a vertical surface in a right-and-left direction is viewed from the front.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Embodiments of the present invention will be described in detail while referring to the accompanying drawings.

[0020]FIG. 1 is a perspective view showing a drum type washing machine according to an embodiment of the present invention as viewed obliquely from above. In FIG. 1, description is made taking the left front as the front and taking the right rear as the rear.

[0021] A case 1 constituting the appearance of the drum type washing machine is so designed that the height thereof in a case where it is set up on the floor (the height from the floor to an upper surface 1A of the case 1) is approximately the height of the waste of a user.

[0022] On the front side of the upper surface 1A of the case 1, an inclined surface 1B inclined downward toward the front is formed. An opening 15 is formed from the upper surface 1A of the case 1 to the inclined surface 1B. An opening/closing cover 14 is attached to the opening 15. The opening/closing cover 14 includes a rear cover 14A covering a portion, formed on the upper surface 1A of the case 1, of the opening 15 and a front cover 14B covering a portion, formed on the inclined surface 1B, of the opening 15. The rear cover 14A has its rear edge attached to the upper surface 1A of the case 1 so as to be rotatable, and the front cover 14B has its rear edge attached to a front edge of the rear cover 14A so as to be rotatable. Both the right and left sides of a front edge of the front cover 14B are slidable forward and backward along inner peripheral edges on the right and left sides of the opening 15.

[0023] The user can open the opening 15 by grasping a holding section 16 formed in the front cover 14B to slide the front cover 14B backward while lifting the rear of the front cover 14B upward so that the front cover 14B and the rear cover 14A are folded.

[0024] An operation display panel 17 for performing various types of setting related to the driving of the drum type washing machine and performing various types of display of the driving conditions, etc. is arranged on the right side of the opening 15 in the inclined surface 1B.

[0025] Approximately circular openings 18 are respectively formed near the centers of both right and left side surfaces of the case 1. A cover 19 is fitted in each of the openings 18 (only the right side surface is viewed in FIG. 1). The opening 18 is a hatch for maintenance. A service man, for example, can maintain the inside of the drum type washing machine by detaching the cover 19 and putting his or her hand into the case 1.

[0026]FIG. 2 is a longitudinal sectional view showing the overall configuration of the drum type washing machine, where a cross section through the washing machine cut along a vertical surface in a right-and-left direction is viewed from the front. FIGS. 3 and 4 are longitudinal sectional views showing the drum type washing machine, where a cross section through the washing machine cut along a vertical surface in a front-and-rear direction is viewed from the left and the right, respectively.

[0027] Referring to FIGS. 2 to 4, an outer tub 2 in an approximately cylindrical shape is provided with its end surface extending in a right-and-left direction inside the case 1. Both end surfaces of the outer tub 2 are respectively closed by end surface walls 21L and 21R.

[0028] The outer tub 2 is supported by a pair of dampers 3F and 3B and a pair of coiled springs (not shown). Specifically, the pair of dampers 3F and 3B connects an inner bottom surface of the case 1 and the outer tub 2, to respectively support a position near the lower front of the outer tub 2 and a position near the lower rear thereof. On the other hand, the pair of coiled springs connects the right and left side surfaces of the case 1 and the outer tub 2, to support positions near the rear of upper ends of the end surface walls 21L and 21R of the other tub 2, respectively.

[0029] A drum 4 in an approximately cylindrical shape for putting laundry in is provided with its end surfaces extending in a right-and-left direction inside the outer tub 2. The drum 4 is accommodated such that its axis is coaxial with the axis of the outer tub 2. Both end surfaces of the drum 4 are respectively closed by end surface walls 41L and 41R, and rotating shafts 51L and 51R are respectively connected to the centers of the end surface walls 41L and 41R. The rotating shafts 51L and 51R respectively extend rightward and leftward from the end surface walls 41L and 41R along the same axis of rotation set in a direction approximately perpendicular to the right and left side surfaces of the case 1, and are respectively held so as to be rotatable in bearings 52L and 52R attached to the outer tub 2.

[0030] A motor 6 for rotating the drum 4 is attached to the left end surface wall 21L of the outer tub 2 through a stator 6A on the left side of the outer tub 2. The motor 6 is coupled to a left end of the rotating shaft 51L using a DD (Direct Drive) system. An outer rotor 6B in the motor 6 is rotated, whereby the rotating shaft 51L is rotated, and the drum 4 is rotated around the axis in the outer tub 2.

[0031] An opening 43 for getting laundry in and out of the drum 4 is formed on a peripheral surface wall 42 of the drum 4. An opening 22 is formed at a position, opposite to the opening 15 of the case 1, in a peripheral surface wall 21 of the outer tub 2. Opening/closing covers 22A and 43A are respectively provided in the opening 22 of the outer tub 2 and the opening 43 of the drum 4, and the laundry is gotten in and out of the drum 4 with the opening/closing covers 22A and 43A opened. The opening/closing cover 43A for the opening 43 of the drum 4 may be so constructed as to be automatically opened and closed, when the opening/closing cover 22A for the opening 22 of the outer tub 2 is opened or closed, in synchronization therewith.

[0032] A locking mechanism 10 for stopping the rotation of the drum 2 is attached to a lower part of the left end wall 21L of the outer tub 2. By the function of the locking mechanism 10, the stop position of the drum 4 is controlled such that the opening 43 is overlapped with the opening 22 of the outer tub 2. Consequently, the laundry can be gotten in and out of the drum 4 through the openings 15, 22, and 43 obliquely from above by opening the opening/closing cover 14 with the rotation of the drum 4 stopped.

[0033] A hose connection port 71 for connecting a water supply hose from outer water works, for example, is provided on the left rear side of the upper surface 1A of the case 1 (see FIG. 3). A water supply tube 72 extends toward the inside of the case 1 from the hose connection port 71. Water supplied through the water supply hose is supplied to the outer tub 2 through the water supply tube 72.

[0034] Furthermore, a drainage port 76 is formed on the right side of a lower end of the peripheral surface wall 21 of the outer tub 2. A drainage tube 75 is connected to the drainage port 76. A drainage valve 77 is provided halfway in the drainage tube 75. Water is supplied with the drainage valve 77 closed, thereby making it possible to store in the outer tub 2 the water supplied through the hose connection port 71. The water stored in the outer tub 2 can be drained off outward through the drainage port 76 and the drainage tube 75 by opening the drainage valve 77.

[0035] A lot of water through holes (not shown) are pieced in the peripheral surface wall 42 of the drum 4. The water supplied to the outer tub 2 flows into the drum 4 through the water through holes. Further, a total of three baffles (not shown) extending in the axial direction for lifting the laundry are provided at intervals of 120 degrees, for example, in the circumferential direction on an inner surface of the peripheral surface wall 42 of the drum 4.

[0036] At the time of washing and rinsing, the drum 4 is rotated with the water stored in the outer tub 2, so that the laundry in the drum 4 is lifted by the baffles, and is naturally dropped toward the surface of the water from a certain degree of height, which operations are repeated. Further, at the time of spin-drying, the drum 4 is rotated at high speed, so that water is wrung out of the laundry in the drum 4 by a centrifugal force, and the water wrung out of the laundry is sprinkled toward the outer tub 2 through the water through holes.

[0037] The drainage tube 75 is branched to the right in its halfway portion. An air trap 11 is attached from the outside to a lower end of the right end surface wall 21R of the outer tub 2, and is connected to the branched drainage tube 75. A water level sensor (not shown) is connected to the air trap 11. The water level sensor can detect the water level inside the outer tub 2 by detecting the pressure of air in the air trap 11.

[0038] A warm water heater 12 is provided in the lowermost part of the outer tub 2. Washing and rinsing can be done at a suitable water temperature by heating the water stored in the outer tub 2 using the warm water heater 12.

[0039] In order to reduce the vibration of the drum 4 at the time of spin-drying, a plurality of (e.g., eight) water storage boxes 8 are attached to an outer surface of the right end surface wall 41R of the drum 4 near its peripheral edge. The water storage boxes 8 are each formed in the shape of a rectangular parallelepiped having an opening 81, and are arranged at equal angular intervals with the opening 81 directed toward the center of rotation (the rotating shaft 51R). A portion of the water supplied to the outer tub 2 from the water supply tube 72 is drained off toward a track drawn by the opening 81 of each of the water storage boxes 8 as the drum 4 is rotated. The water can be stored by a centrifugal force in each of the water storage boxes 8 by draining the water off while rotating the drum 4 at a predetermined speed.

[0040] When an eccentric load in the direction of rotation is produced in the drum 4 by the uneven distribution of the laundry, each of the water storage boxes 8 is made almost full of water. From the state, such control as to instantaneously reduce the rotational speed of the drum 4 is carried out such that the water is spilled from the water storage box 8 at an angular position in closest proximity to the eccentric load. If the amount of weight reduced by spilling the water from the water storage box 8 is almost balanced with the eccentric load, both are canceled. Accordingly, the eccentric load in the direction of rotation produced in the drum 4 is reduced, thereby making it possible to reduce the vibration caused by the eccentric load (the uneven distribution of the laundry).

[0041] In order to further restrain the vibration of the drum 4 at the time of spin-drying, a fluid balancer 9 in an annular shape is attached along a peripheral edge of the left end surface wall 41L of the drum 4. The fluid balancer 9 has four fluid paths 91 formed therein along its circumference. A predetermined amount of liquid is sealed in each of the fluid paths 91. Further, each of the fluid paths 91 has a partition plate (not shown) provided therein for each predetermined angle (e.g., approximately 60 degrees) along its circumference. The liquid in each of the fluid paths 91 can be freely circulated through a clearance between the partition plate and an inner surface of the fluid balancer 9. Consequently, the liquid in the fluid balancer 9 is unevenly distributed so as to make the drum 4 vibrate in approximately the same phase as that of the vibration caused by the uneven distribution of the laundry while the drum 4 is being rotated at low speed (approximately 100 rpm), while being unevenly distributed so as to make the drum 4 vibrate in the opposite phase to that of the vibration caused by the uneven distribution of the laundry when the rotational speed of the drum 4 exceeds a certain speed (approximately 300 rpm). When the drum 4 is rotated at high speed, therefore, the vibration caused by the uneven distribution of the laundry can be set off by the vibration caused by the uneven distribution of the liquid in the fluid balancer 9, thereby making it possible to restrain the vibration of the drum 4.

[0042] The drum type washing machine also has the function of drying the laundry which has been spin-dried. A drying unit U is attached to an outer surface of the right end surface wall 21R of the outer tub 2. As shown in FIG. 4, the drying unit U comprises an air path member 31 constituting an air path for introducing air outside the case 1 which has sucked in from a suction port 30 through which the inside and the outside of the case 1 communicate with each other upward, a fan 32 arranged at a final end of the air path member 31 for feeding the air from the outside of the case 1 into the outer tub 2, a drying hood 33 for introducing the air from the fan 32 into the outer tub 2, and a warm air heater 34 arranged in the drying hood 33 for heating the air to be fed into the outer tub 2. At the time of drying, operations of rotating the drum 4 while blowing warm air in the outer tub 2 from the drying unit U, to lift the laundry in the drum 4 by the baffles and naturally drop the laundry from a certain degree of height are repeated. Consequently, the laundry can be satisfactorily dried.

[0043]FIGS. 5 and 6 are respectively a right side view and a front view showing the outer tub 2 viewed in a case where it is taken out and the drum 4 is omitted. Referring to FIGS. 5 and 6, on the outer peripheral surface wall 21 of the outer tub 2, an electrolytic device 60 for electrolyzing the water stored in the outer tub 2 is mounted at a left end on the front side of its lower end.

[0044] The electrolytic device 60 has an electrolytic tub 62 in a hollow shape comprising a plurality of electrode plates 61 in its inner part, and two connection tubes 63A and 63B for connecting the electrolytic tub 62 to the outer tub 2 to circulate the water stored in the outer tub 2 into the electrolytic tub 62. Particularly, the connection tube 63A extends horizontally in a tangential direction from the lowermost end of the outer tub 2.

[0045] On the peripheral surface wall 21 of the outer tub 2, an inlet tube 64A and an outlet tube 64B respectively corresponding to the connection tubes 63A and 63B are provided in a state protruding outward at its mounting positions of the electrolytic device 60. The inlet tube 64A and the outlet tube 64B are arranged in the vertical direction, and respectively protrude forward in the horizontal direction. The electrolytic device 60 is mounted on the outer tub 2 by respectively connecting the connection tubes 63A and 63B to the inlet tube 64A and the outlet tube 64B corresponding thereto through packings 65 as well as inserting screws into the peripheral surface wall 21 of the outer tub 2 through a plurality of (e.g., four) screw holes 66 provided in the electrolytic tub 62. Consequently, the electrolytic tub 62 is obliquely attached so as to be parallel to the peripheral surface wall 21 of the outer tub 2 in a state where it is opposed to the peripheral surface wall 42 of the drum 4, thereby making it possible to take the water stored in the outer tub 2 into the electrolytic tub 62.

[0046] Since the electrolytic tub 62 is provided in a state where it is opposed to the peripheral surface wall 42 of the drum 4, the water stored in the outer tub 2 which flows as the drum 4 is rotated smoothly enters the electrolytic tub 62. Consequently, the electrolysis of the water is speeded up. The electrolyzed water improves the detergency.

[0047] Since the electrolytic tub 62 is obliquely provided along the peripheral surface wall 21 of the outer tub 2, the electrolytic device 60 can be arranged in a narrow mounting space at a lower front corner of the outer tub 2.

[0048] Since the inlet tube 64A and the outlet tube 64B are provided in a state where there is a difference in height therebetween, the flow of the water stored in the outer tub 2 which flows as the drum is rotated differs between the vicinity of the inlet tube 64A and the vicinity of the outlet tube 64B. Consequently, the flow of the water in the electrolytic device 60 can be improved, so that the electrolysis of the water is speeded up, thereby improving the detergency.

[0049] At the time of drainage, the water in the electrolytic device 60 flows from the higher outlet tube 64B to the lower inlet tube 64A. Accordingly, the water can be prevented from remaining stored in the electrolytic device 60. Consequently, the electrode plate 61 can be prevented from corroding, thereby making it possible to improve the durability.

[0050] The electrolytic device 60 is attachable and detachable by loosening the four screws to disconnect the two connection tubes 63A and 63B and the inlet tube 64A and the outlet tube 64B respectively corresponding thereto from each other. Consequently, the electrolytic device 60 can be detached and maintained, thereby making it possible to lengthen the life of the electrolytic device 60.

[0051] The electrolytic tub 62 has a pair of connection terminals 67 provided in a state protruding leftward from its left side surface, for example. The connection terminals 67 are connected to the plurality of electrode plates 61 inside the electrolytic tub 62. Two lead wires respectively connected to the positive pole and the negative pole of a power supply circuit provided inside the drum type washing machine are connected to the pair of connection terminals 67 through waterproof connectors (not shown), to energize the plurality of electrode plates 61. The water taken in the electrolytic tub 62 in the electrolytic device 60 from the outer tub 2 is subjected to electrolysis processing.

[0052] The plurality of electrode plates 61 are arranged at positions where they are immersed in the water stored in the outer tub 2. Consequently, the water and a slight amount of chlorine contained therein chemically react, thereby producing active oxygen (O₂ ⁻), hypochlorous acid (HClO), etc. The functions of the products can prevent dirt removed from the laundry from adhering to the laundry again at the time of washing and can sterilize the laundry by a sterilizing effect at the time of rinsing. Consequently, the detergency can be improved.

[0053] Both the inlet tube 64A and the outlet tube 64B are arranged at positions lower than the water level of the water stored in the outer tub 2. Consequently, the water flows more smoothly inside the electrolytic device 60, so that the electrolysis is further speeded up, thereby improving the detergency. The outlet tube 64B may be so arranged as to be at a position higher than the water level of the water stored in the outer tub 2.

[0054] In the present embodiment, at the time of washing and rinsing, the drum 4 is alternately rotated in a clockwise direction and a counterclockwise direction in FIG. 5 around its axis by rotating the driving of the motor 6 in a forward/backward direction for each predetermined time period. On the other hand, at the time of spin-drying, the drum 4 is rotated at high speed in a counterclockwise direction in FIG. 4 around its axis.

[0055] The inlet tube 64A protrudes forward in a tangential direction from the lowermost end of the peripheral surface wall 21 of the outer tub 2. When the drum 4 is rotated in a clockwise direction in FIG. 5, the water stored in the outer tub 2 which flows in a clockwise direction as the drum 4 is rotated enters easily the electrolytic device 60 through the inlet tube 64A. At the time of washing and rinsing, therefore, the water smoothly enters the electrolytic device 60 when the drum 4 is rotated in a clockwise direction. Accordingly, the electrolysis of the water can be speeded up, thereby making it possible to improve the detergency. On the other hand, at the time of spin-drying, the drum 4 is rotated in the direction in which the water wrung out of the laundry does not easily enter the inlet tube 64A (in a counterclockwise direction), thereby making it possible to satisfactorily drain the water off in the electrolytic device 60.

[0056] In the present embodiment, the drum 4 is stopped only for a predetermined time period (e.g., approximately five minutes) until rinsing is started after the laundry has been washed. Consequently, the electrolytic device 60 electrolyzes the water during the predetermined time period, thereby making it possible to increase the concentrations of active oxygen and hypochlorous acid produced by the electrolysis in the vicinity of the electrolytic device 60. Thereafter, rinsing is performed, thereby making it possible to improve the sterilizing effect.

[0057] The electrolytic device 60 may electrolyze the water only when the drum 4 is rotated in a clockwise direction at the time of washing and rinsing. In this case, the electrolysis is performed only when the water easily enters the electrolytic tub 60, thereby making it possible to efficiently electrolyze the water as well as lengthen the life of the electrolytic device 60.

[0058] In the present embodiment, not only the laundry in the drum 4 but also the electrode plates 61 included in the electrolytic device 60 can be dried by the function of the drying unit U. Consequently, the electrode plate 61 can be prevented from corroding, thereby making it possible to improve the durability.

[0059] The electrolytic device 60 performs the function of not only electrolyzing the water at the time of washing and rinsing but also detecting whether or not bubbles remain in the outer tub 2 before or during spin-drying. When bubbles remain in the electrolytic tub 60 after the rinsing is terminated, a current flows through the bubbles between the electrode plates 61 in the electrolytic device 60. Consequently, it is possible to detect whether or not bubbles remain in the outer tub 2 by detecting the electrical resistance of the current. Specifically, the resistance value is low when bubbles remain in the outer tub 2, while being high when no bubbles remain. When it is detected that bubbles remain in the outer tub 2, the bubbles may be removed by draining a predetermined amount of water off into the outer tub 2, for example.

[0060] The removal of the bubbles remaining in the outer tub 2 can prevent the number of rotations of the drum 4 from not being increased because the bubbles serve as a resistance at the time of spin-drying, thereby making it possible to improve the spin-drying performance.

[0061]FIG. 7 is a longitudinal sectional view showing the overall configuration of a drum type washing machine according to another embodiment of the present invention, where a cross section through the washing machine cut along a vertical surface in a right-and-left direction is viewed from the front. The drum type washing machine according to the present embodiment is the same as the drum type washing machine according to the first embodiment except that they differ in the mounting manner of an electrolytic device 160. Accordingly, the same components are assigned the same numerals and hence, the description thereof is not repeated.

[0062] The electrolytic device 160 is attached to a lower end of a right end surface wall 21R of an outer tub 2 from outside. The electrolytic device 160 has an electrolytic tub 162 in a hollow shape comprising a plurality of electrode plates 161 in its inner part, and two connection tubes 163A and 163B for connecting the electrolytic tub 162 to the outer tub 2 to circulate water stored in the outer tub 2 in the electrolytic tub 162.

[0063] On the right end surface wall 21R of the outer tub 2, two projection tubes 164A and 164B respectively corresponding to the connection tubes 163A and 163B are provided in a state protruding outward at its mounting positions of the electrolytic device 160. The two projection tubes 164A and 164B are arranged in the vertical direction, and respectively protrude rightward in the horizontal direction. The electrolytic device 160 can take the water stored in the outer tub 2 into the electrolytic tub 162 with the electrolytic tub 162 attached in a state opposite to a right end surface wall 41R of a drum 4.

[0064] Although in the present embodiment, the electrolytic device 160 is provided not on a peripheral surface wall 42 of the drum 4 but opposite to the end surface wall 41R, the water stored in the outer tub 2 which flows as the drum 4 is rotated does not enter easily either of the two projection tubes 164A and 164B. Consequently, waste thread contained in the water stored in the outer tub 2 can be prevented from entering the electrolytic device 160, thereby making it possible to prevent breakdown of the electrolytic device 160.

[0065] The present invention is not limited to the contents of the above-mentioned embodiments. Various types of changes can be made within the scope of claims.

[0066] Although in the above-mentioned embodiments, description was made of a case where the drum 4 is rotated around an axis of rotation extending in the horizontal direction, that is, an axis of rotation set at a predetermined angle of zero to the horizontal direction. However, the axis of rotation of the drum is not limited to the same. For example, the drum 4 may be rotated around an axis of rotation set within a range of predetermined angles from approximately zero to 30 degrees to the horizontal direction.

[0067] Although description was made using a so-called top loading drum type washing machine in which the opening 15 for getting laundry in and out of the drum is formed on the upper surface 1A of the case 1, the present invention is also applicable to a drum type washing machine in which an opening for getting laundry in and out of a drum is formed on a front surface of a case, for example.

[0068] The mounting position of the electrolytic device is not limited to the mounting positions in the above-mentioned two embodiments. For example, the electrolytic device may be arranged inside the outer tub, for example. For example, the electrolytic device may be so constructed that a peripheral surface wall of an outer tub at a position where it is mounted is formed in a state protruding outward, and the electrolytic device is attached to the inside of a protruding portion of the peripheral surface wall. 

What is claimed is:
 1. A drum type washing machine comprising: an outer tub capable of storing water at the time of washing; and a drum provided in the outer tub and rotatable around an axis of rotation set within a range of predetermined angles to the horizontal direction, the outer tub being provided with an electrolytic device having an electrode plate provided, when water is stored in the outer tub, at a position where it is immersed in the stored water such that the stored water can be electrolyzed.
 2. The drum type washing machine according to claim 1, wherein the drum has a peripheral surface wall that can be rotated around the axis of rotation, the electrolytic device comprising the electrode plate and an electrolytic tub accommodating the electrode plate, the electrolytic tub being attached to a position opposite to the peripheral surface wall of the drum.
 3. The drum type washing machine according to claim 2, wherein the electrolytic device has an inlet, which communicate through the electrolytic tub and the outer tub, for allowing the water stored in the outer tub to enter the electrolytic tub, and an outlet, which communicate through the electrolytic tub and the outer tub, for returning the water in the electrolytic tub to the outer tub, the inlet and the outlet being provided in a state where there is a difference in height therebetween.
 4. The drum type washing machine according to claim 3, wherein the inlet is so arranged as to be at a position lower than the water level of the water stored in the outer tub, and the outlet is so arranged as to be at a position higher than the water level of the water stored in the outer tub.
 5. The drum type washing machine according to claim 3, wherein the inlet and the outlet are so arranged as to be respectively at positions lower than the water level of the water stored in the outer tub.
 6. The drum type washing machine according to claim 3, wherein the inlet faces the tangent of the peripheral surface wall of the drum.
 7. The drum type washing machine according to claim 6, wherein the drum is rotated toward the inlet from the outlet at the time of spin-drying.
 8. The drum type washing machine according to claim 6, wherein the drum is alternately rotated in a direction from the outlet to the inlet and a direction opposite thereto at the time of washing and rinsing, and the electrolytic device electrolytes the water stored in the outer tub only when the drum is rotated in the opposite direction.
 9. A drum type washing machine comprising: an outer tub in the shape of a cylinder arranged so as to extend sideward for storing water at the time of washing; and a drum accommodated in the outer tub approximately coaxially and rotated around an axis of rotation set within a range of predetermined angles to the horizontal direction with laundry put therein, further comprising an inlet provided in a cylindrical portion of the outer tub and directed sideward from a lower end of the cylinder; an outlet provided in the cylindrical portion of the outer tub and opened sideward from a position higher than the inlet by a predetermined distance, and an electrolytic device, connected to the inlet and the outlet and attached obliquely so as to be parallel to a surface of the outer tub, for electrolyzing water flowing in through the inlet and returning the water to the outer tub from the outlet.
 10. The drum type washing machine according to claim 9, wherein the electrolytic device is attached to the outer tub so as to be detachable.
 11. A drum type washing machine comprising: an outer tub capable of storing water at the time of washing; and a drum, provided in the outer tub and rotated around an axis of rotation set within a range of predetermined angles to the horizontal direction, for putting laundry in, an electrolytic device for causing the water stored in the outer tub to flow in, electrolyzing the water, and returning the water to the outer tub being provided on an end surface of the outer tub opposite to an end surface along the axis of rotation of the drum.
 12. A drum type washing machine comprising: an outer tub capable of storing water at the time of washing; a drum, provided in the outer tub and rotated around an axis of rotation set within a range of predetermined angles to the horizontal direction, for putting laundry in, an electrolytic device for electrolyzing the water stored in the outer tub; and a drying device for feeding warm air into the outer tub in order to dry the laundry which has been spin-dried.
 13. The drum type washing machine according to claim 12, wherein the drum has a peripheral surface wall rotated around the axis of rotation, and the electrolytic device is attached to the outer tub where a position is opposite to the peripheral surface wall of the drum.
 14. The drum type washing machine according to claim 1, wherein the drum is stopped for a predetermined time period until rinsing is started after the laundry has been washed, and the electrolytic device electrolytes the water stored in the outer tub during the predetermined time period.
 15. A drum type washing machine comprising: an outer tub capable of storing water at the time of washing; and a drum, provided in the outer tub and rotated around an axis of rotation set within a range of predetermined angles to the horizontal direction, for putting laundry in, further comprising an electrolytic device having an electrode plate for electrolyzing the water stored in the outer tub, and capable of detecting whether or not bubbles remain in the outer tub by causing a current to flow in the electrode plate before or during spin-drying to detect its electrical resistance. 